Non-Melanoma Skin Cancer May Cut Alzheimer's Risk by 80 Percent, Study
Skin cancer may lower the risk of developing Alzheimer's disease by up to 80 percent, a new study suggests.
A new study published Wednesday in the journal Neurology reveals that skin cancer patients are significantly less likely to develop the neurodegenerative disease. However, researchers noted that the association does not apply to melanoma, a less common but more aggressive type of skin cancer.
Researchers studied 1,102 people in New York City with an average age of 79 who did not have dementia at the start of the study. Researchers followed the participants for an average of 3.7 years. At the beginning of the study, 109 people reported that they had skin cancer in the past, and during the study 32 developed skin cancer and 126 people developed dementia, including 100 with Alzheimer's dementia.
The findings show that people who had skin cancer were almost 80 percent less likely to develop Alzheimer's disease than people who did not have skin cancer. Researchers found that of the 141 people with skin cancer, only two developed Alzheimer's disease. However, researchers noted that the link was not found with other types of dementia, like vascular dementia.
While researchers still do not know the exact reason for this possible protective effect of skin cancer, they say one possible explanation could be exercise.
"One possible explanation could be physical activity," researcher Dr. Richard B. Lipton, of Albert Einstein College of Medicine in Bronx, NY, and a Fellow of the American Academy of Neurology, said in a news release.
"Physical activity is known to protect against dementia, and outdoor activity could increase exposure to UV radiation, which increases the risk of skin cancer," he said.
However, Lipton noted that other factors including genetic makeup may also play a role, as physical activity does not reduce the risk of Alzheimer's disease to the extent found in the link between skin cancer and Alzheimer's disease.
However, researchers stress that the latest findings do not mean that people should throw away their sunscreens and stop taking measures to prevent skin cancer.
"People should continue to wear sunscreen, avoid the sun during midday and wear clothing to protect their skin," he said. "The hope is that these results help us learn more about how Alzheimer's develops so we can create better preventive methods and treatments."
Surprisingly, the link between skin cancer and Alzheimer's disease is not new.
In 2012, a study published in the journal Science found that a skin cancer drug known as bexarotene, which treats T cell lymphoma, rapidly revered Alzheimer's disease in mice. Within hours of taking bexarotene, the abnormal protein plaques in mice with Alzheimer's had started clearing out of their brains. The study found that the drug worked with "unprecedented speed" at reducing soluble amyloid by 25 percent and its buildup in the brain by 50 percent in just three days. Researchers said that mice treated with the drug also regained some of the cognitive and memory functions they lost. They found that mice given the drug made significant improvements in nest building, maze performance and remembering electrical shocks.